1. Field of the Invention
The present invention relates to a hinge connecting mechanism employable for a container having a lid integrally attached thereto wherein the lid and a housing of the container are molded integral with each other via a hinge portion having a small thickness.
2. Prior art
As is well known, containers molded of material such as plastic, rubber or the like, while having a lid integrally attached thereto, are put into practical use in many industrial fields. With the containers each having a lid integrally attached thereto, it is possible to mold each of the containers in an integral structure by employing an injection molding process using an injection molding die. This has the advantageous effect that the containers can be produced at a reduced cost by using a mass production line. For this reason, the containers, each having a lid integrally attached thereto, are practically used in wide variety of applications ranging from containers having intricate structures to containers having simple structures.
Not only compressible stress, but also tensile stress arise in a hinge portion employed for a container of the foregoing type having a lid integrally attached thereto when the hinge portion is rotated and expanded as the lid is opened and closed. In the above circumstances, the hinge portion is usually designed to have a small thickness in order to enlarge a radius of curvature of the hinge portion at the time of bending thereof, so as to sufficiently withstand the compressible stress and the tensile stress which arise in the hinge portion when the lid is opened and closed.
Containers of the foregoing type, each having a lid integrally attached thereto, are shown by a connector used for achieving electrical connection therewith as disclosed in Unexamined Japanese Utility Model Publication No. Sho 62-82575. A plate member (serving as a lid) molded integral with a connector housing via a hinge portion is doubly engaged with an electrode terminal received in the connector housing. Improved reliability with respect to the electrical connection is achieved by eliminating any possibility that the electrode terminal can become disconnected from the connector housing in the rearward direction.
A typical conventional connector of the foregoing type is described below with reference to FIG. 4.
As shown in FIG. 4, a connector housing 1 having a terminal accommodating chamber 2 formed therein includes a plate member 9 on an upper wall 3 thereof. The plate member 9 is connected in a hinged fashion to the upper wall 3 via an elastic hinge portion 4 having a small thickness while a terminal fixing member 5 is disposed at the free end of the plate member 9. In addition, a rectangular opening portion 6 is formed through the upper wall 3 of the connector housing 1 so as to allow the terminal fixing member 5 to be inserted into the terminal accommodating chamber 2 therethrough. When an electrode terminal 11 is assembled with the connector housing 1, it is first inserted into the terminal accommodating chamber 2 from the rear side of the connector housing 1. Subsequently, a flexible engagement lance (not shown) disposed in the terminal accommodating chamber 2 is engaged with a hole (not shown) formed through the rear surface of the electrode terminal 11. Thereafter, the plate member 9 is rotated in a direction marked by arrow f, so that the terminal fixing member 5 is inserted into the terminal accommodating chamber 2 through the rectangular opening portion 6 until holding projections 5b and 5c projecting outside of the terminal fixing member 5 are engaged with an inner surface 3a of the upper wall 3 along a front edge 3b of the rectangular opening portion 6. With this construction, the electrode terminal 11 inserted into the terminal accommodating chamber 2 is doubly engaged with the connector housing 1. This is because a terminal fixing face 5a of the terminal fixing member 5 is brought in engagement with a rear end surface 11d of an electrical contact member 11c of the electrode terminal 11.
Upon completion of the assembling operation, set forth above, the intensity of the terminal holding power for firmly holding the electrode terminal 11 in connector housing 1, is substantially increased. This increased intensity is caused by addition of the terminal holding power derived from the engagement lance and the terminal holding power derived from the terminal fixing member 5, resulting in the increased reliability of the connector with respect to the electrical connection between the connector housing 1 and the electrode terminal 11.
With the conventional connector constructed in the above-described manner, however, a malfunction arises when the plate member 9 is rotated in the direction marked by arrow f, so as to be engaged with the connector housing 1 while the holding projection 5c of the terminal fixing member 5 is engaged with the front edge 3b of the rectangular opening portion 6. The malfunction arises because of the considerably high intensity of the power required for raising up the plate member 9 is concentratively applied to the hinge portion 4. This is due not only because of the small thickness of the hinge portion 4, but also because of the short length between the connector housing 1 and the plate member 9. This results in the hinge portion 4 being undesirably broken or torn away from the connector housing 1. It should be noted that when a certain intensity of exterior power, effective for drawing the electrode terminal 11 away from the connector housing 1 in the direction marked by the arrow F, is applied to the electrode terminal 11, the power acting on the hinge portion 6 is intensified by the terminal holding power of the terminal fixing member 5 which effectively stands against the exterior power so as to prevent the electrode terminal 11 from being disconnected from the terminal housing 1 in the rearward direction.